JP4593210B2 - Method and apparatus for protecting reaction vessel of high pressure annealing apparatus - Google Patents

Description

  The present invention relates to a high pressure annealing apparatus, and more particularly, to a method for protecting a reaction vessel of a high pressure annealing apparatus. More specifically, when the heating means arranged in the high-pressure annealing apparatus and heating and adjusting the inside of the reaction container containing the reaction gas does not function for some reason, the temperature inside the reaction container The inside of the reaction vessel falls to a reduced pressure state, and as a result, the reaction vessel may be damaged.In this case, the pressure inside the high-pressure annealing apparatus and the pressure inside the reaction vessel And a method and an apparatus for protecting the reaction vessel in the high-pressure annealing apparatus from being damaged by adjusting the pressure so as to be relatively balanced.

  In an apparatus having a double sealed chamber composed of two regions having a small inner sealed container chamber or reaction vessel inside a large outer sealed chamber such as a high pressure annealing apparatus, an outer sealed chamber is optionally provided. When adjusting the pressure between the inner sealed chamber and the inner sealed chamber, the internal pressure is adjusted by supplying a necessary amount of nitrogen gas, steam, air, etc. via valve means attached to a conduit communicating with each sealed chamber. This is well known in the art.

  Also, a safety valve with a bellows attached to a steam boiler, hot water boiler, pressure vessel, etc. to prevent gas from entering from the outside and hardly affected by the pressure on the secondary side, Under conditions where the pressure fluctuates from atmospheric pressure to vacuum pressure or when the valve is stopped, both the primary side and secondary side of the valve have an airtight welded joint structure that prevents gas from entering through the valve body, and the secondary side is a container. A safety valve is also known which is welded to a sealed portion such as the above (for example, see Patent Document 1).

  Further, a valve device used for a decompression and pressurization container, wherein a leg portion of one T-shaped tube is connected to the container, and a leg portion of another T-shaped tube is connected to a vacuum pump system. The ends of one arm of one T-shaped tube and the other arm of another T-shaped tube are joined in a state where an annular valve seat having an inner diameter d is sandwiched, and the inside of the arm portions of both joined T-shaped tubes is its axis. A disc valve of diameter> d fixed to the stem in a state of being vertically penetrated by a stem extending in the direction so as to abut on the container side surface of the annular valve seat, The other one arm part of the T-shaped tube is closed, and the stem extends through the center of the closed end part so that the extension part of the stem is axially slidable and airtight and extends to the outside. The end of the other arm of the T-tube on the vacuum pump system side is closed, and the extension of the stem is slidable in the axial direction through the center of the closed end. It is pivotally attached in an airtight state and extends to the outside, and the disc valve extends in the stem axis direction over a predetermined distance from the valve seat contact position to a position that substantially crosses the leg portion that forms the connection to the container. There is also known a valve device provided with means for driving the stem from the outside through its external extension so that it can move and reversely move (see, for example, Patent Document 2).

  Furthermore, it is a small and highly accurate valve device that quickly responds to pressure fluctuations in two region chambers having an outer sealed chamber and an inner sealed chamber that are sealed to each other and limits the pressure variation in the inner and outer regions as much as possible. The valve body accommodating member, the substrate, the cylindrical valve body, the top-shaped valve body, the floating plate, the guide rod, the stopper rod, the large-diameter coil spring, and the small-diameter coil spring. The one end of the valve body housing member communicates with one of the region chambers, and the substrate divides the two regions by closing the other end of the valve body housing member, and the two regions in the central portion. A perforated valve plate in which the cylindrical valve body penetrating the opening is a valve plate having an opening for receiving the coma-shaped valve body, Cylindrical portion that rises from the periphery of the valve plate and extends through the opening of the substrate to the other region chamber A non-perforated valve having a plurality of airflow penetrating means and a coma-shaped valve body located within the cylindrical portion of the tubular valve body on the other region chamber side And a guide portion that is slidably guided within the opening of the tubular valve body and extends to one region chamber side, and the floating plate is configured to open the open end of the cylindrical portion of the tubular valve body. The guide rod is closed and has a through hole. One end of the guide rod is slidably received in the through hole, the other end is supported by the top-shaped valve body, and the stopper rod is a floating plate. A valve device comprising: a large-diameter coil spring disposed between the floating plate and the substrate; and a small-diameter coil spring disposed between the floating plate and the guide rod. The same applicant previously applied (for example, refer to Patent Document 3).

JP 2001-295952 A Japanese Patent No. 2949024 Japanese Patent Application No. 2002-300288

  However, the valve devices described in Patent Documents 1 and 2 are unsuitable for installation in a narrow room because the device itself is large. Also, for example, in an apparatus that uses quartz glass that can withstand high temperatures as the inner sealed chamber material (for example, a certain type of high-pressure annealing apparatus), the quartz glass itself is expensive, so the thickness is formed as thin as possible. For this reason, when the difference between the internal and external pressures in the quartz glass chamber increases, the glass may be easily broken. Such damage to the quartz glass chamber causes a great economic loss, and it is necessary to prevent such damage as much as possible. For this purpose, a valve device having a highly accurate differential pressure detection function and a pressure adjustment function associated therewith is required. In this respect, the above-mentioned Patent Document 3 provides a small and highly accurate valve device, and substantially solves the problems of the above two Patent Documents.

  However, all of the devices described in these patent documents are reaction vessels arranged in a high-pressure annealing device, and heating means for heating and adjusting the inside of the reaction vessel containing the reaction gas therein. For example, when the power supply of the heating means is turned off for some reason while the worker has stopped functioning due to an unexpected power failure, or the reaction gas is filled in the reaction vessel, or the heating means has failed. There is nothing to consider about. Therefore, when the function of such a heating means is stopped, the temperature inside the reaction vessel is lowered and the inside of the reaction vessel is depressurized, and as a result, a pressure difference is generated inside and outside the reaction vessel. The pressure difference increases with the temperature drop in the reaction vessel, and there is a risk that the reaction vessel will eventually be damaged. Usually, this reaction vessel is made of an expensive material, and this breakage causes a great economic loss. Moreover, if such a breakage accident occurs during the reaction process, the work being processed is also damaged. In such a case, the present invention aims to provide a method for protecting an expensive reaction vessel from damage by adjusting the pressure inside and outside the reaction vessel to be relatively balanced in the high-pressure annealing apparatus. To do.

  A pressure vessel, a reaction vessel accommodated inside the pressure vessel, and heater means arranged around the reaction vessel in a defined air space between the pressure vessel and the reaction vessel. In a high-pressure annealing apparatus, when the temperature inside the reaction vessel drops due to the inactivation of the heater means and the pressure inside the reaction vessel is reduced, the reaction vessel is protected from damage. Prepare pressure sensors that respond to fluctuations, prepare pressure sensors that respond to pressure fluctuations in the airspace, connect these pressure sensors to an uninterruptible power supply that starts immediately when the heater means does not operate, and synchronize both pressure sensors. However, it is a protection method comprising the steps of maintaining the pressure inside and outside the reaction vessel at the same value by lowering the pressure outside the reaction vessel.

  According to the high-pressure annealing apparatus 10 of the present invention, the heater 32 as a heating means arranged around the annealing chamber 28 becomes inoperative for some reason, the temperature inside the annealing chamber 28 decreases, and the processing chamber 28 Even if the internal pressure decreases, the uninterruptible power supply 58 that starts simultaneously with the inactivation of the heater 32 starts the operation of the pressure sensors 54 and 56, thereby synchronizing the pressure outside the annealing chamber 28, that is, in the air space 30. Descent. For this reason, an accident that the pressure inside and outside the reaction vessel 20 is balanced and the reaction vessel 20 is damaged due to the pressure difference can be completely prevented. For this reason, even if the thickness of the expensive quartz glass is made thinner than before, the quartz glass is not damaged. Therefore, expensive quartz glass can be used very effectively and effectively. Therefore, the large economic loss due to the damage of the quartz glass chamber as before has been completely eliminated. Further, since no gas is introduced from the outside into the annealing chamber during the pressure adjustment, there is no damage to the work in progress.

  In the following, a method for protecting the reaction vessel from breakage by adjusting the pressure inside and outside the reaction vessel when the temperature inside the reaction vessel is lowered in a high-pressure annealing apparatus equipped with a reaction vessel inside. State. However, the method of the present invention is not limited only to the high pressure annealing apparatus using quartz glass as the reaction vessel, and the high pressure annealing apparatus using other materials, and various types having the same dual structure. It will be apparent to those skilled in the art that the control device, the processing device, and the like can be used appropriately.

  FIG. 1 is a schematic view of a high pressure annealing apparatus 10 embodying the method of the present invention. The high-pressure annealing apparatus 10 has a sturdy pressure vessel 12 generally made of steel. As is known to those skilled in the art, the pressure vessel 12 is composed of an upper vessel 14 and a lower vessel 16 that are separable from each other, and the upper vessel and the lower vessel are hermetically sealed with a sealing means 18. It is formed by. As is well known, the pressure vessel 12 is desirably cooled around the periphery thereof by means (not shown) such as a cooling jacket.

  Inside the pressure vessel 12, a reaction vessel 20 made of, for example, expensive quartz glass is fixed at a predetermined position by a known means. As known to those skilled in the art, the reaction vessel 20 includes a reaction vessel body 22 having an inverted cylindrical shape, and an end cap 24 having a generally upper bay shape that closes the lower end of the reaction vessel body 22. And a sealing means 26 such as an O-ring that hermetically seals the lower end portion of the reaction vessel main body 22 and the outer peripheral edge of the end cap 24. The reaction vessel main body 20 has an annealing chamber 28 formed therein. As is well known to those skilled in the art, the processing chamber 28 has a workpiece to be subjected to high-pressure annealing such as a thin plate-shaped glass substrate for liquid crystal or a silicon wafer, that is, an article to be processed (not shown) and these thin plate-shaped workpieces. A cassette (not shown) for holding the articles at a predetermined interval is arranged. The end cap 24 separates the inside of the pressure vessel 12 and the inside of the reaction vessel 20. Further, in the air space 30 between the pressure vessel 12 and the reaction vessel 20, in order to heat and adjust the inner part of the reaction vessel 20, the periphery of the reaction vessel 20 (in the illustrated example, the outer surface of the reaction vessel main body 22 and As is well known, a plurality of heaters 32 as heating means are disposed on the lower surface of the end cap 24.

  A first air supply pipe 34 communicates with the annealing chamber 28 from the outside of the pressure vessel 12 through the air space 30. The first air supply pipe 34 is provided with valve means 36. The first air supply pipe 34 supplies pure water, liquid nitrogen, or pure water gas or nitrogen gas into the annealing chamber 28 from the outside. As is well known, the first air supply pipe 34 enters the annealing chamber 28 in a high-temperature reduced pressure state. Most of the introduced pure water or liquid nitrogen immediately changes to a gaseous state. These gases anneal the workpiece, that is, the article to be processed. Furthermore, another first exhaust pipe 38 communicates with the annealing chamber 28 through the airspace 30 to the outside of the pressure vessel 12. Valve means 40 is provided in the first exhaust pipe 38. As is well known to those skilled in the art, the first exhaust pipe 38 initially adjusts the interior of the annealing chamber 28 to a reduced pressure state, and further, the annealing chamber 28 is optimally annealed during the annealing process. In order to put it under conditions, it has a function of adjusting the internal pressure of the annealing chamber 28 as necessary. In FIG. 1, an annular groove portion opened in the annealing chamber 28 is joined to the outer peripheral edge of the end cap 24 and the lower end portion of the reaction vessel main body 22 which are sealed and joined by the sealing means 26. 42 is formed, liquid pure water or nitrogen is held in the groove 42, and the annealing chamber 28 is always filled with pure water or nitrogen gas.

  Similarly, the second air supply pipe 44 and the second exhaust pipe 46 communicate with the air space 30 formed so as to surround the reaction container 20 inside the pressure container 12 through the pressure container 12. Valve means 48 and 50 are provided in the second air supply pipe 44 and the second exhaust pipe 46, respectively. Further, in the illustrated example, valve means 52 is provided in a portion of the first exhaust pipe 38 passing through the air space 30. This valve means 52 is operated so as to open and maintain a pressure balance between the pressure inside the annealing chamber 28 and the pressure inside the air space 30. Valve devices as described can be used. As will be apparent to those skilled in the art, the second air supply pipe 44 and the second exhaust pipe 46 change the external conditions of the annealing chamber 28 in response to the pressure conditions of the annealing chamber 28 inside the reaction vessel 20, thereby annealing. The pressure difference between the inside and outside of the processing chamber 28 is kept as small as possible, thereby preventing the fragile reaction vessel from being damaged as much as possible. In the illustrated embodiment, the first exhaust pipe 38 and the second exhaust pipe 46 are equipped with known pressure sensors 54 and 56. Of course, since the first exhaust pipe 38 and the first air supply pipe 34 exhibit the same pressure, it is natural that the first air supply pipe 34 may be equipped with a pressure sensor 54 instead of the first exhaust pipe 38. Similarly, since the second exhaust pipe 46 and the second air supply pipe 44 exhibit the same pressure, it is natural that the second air supply pipe 44 may be equipped with a pressure sensor 56 instead of the second exhaust pipe 46. That is, the pressure sensor 54 may be attached to any of the first pipe means 34 and 38, and the pressure sensor 56 may be attached to any of the second pipe means 44 and 46. However, the automatic valves activated by the pressure sensors 54 and 56 are preferably automatic valves 40 and 50 mounted on the exhaust pipes 38 and 46, respectively. These pressure sensors 54 and 56 are connected to an uninterruptible power supply (for example, a battery) 58. The uninterruptible power supply 58 preferably has a capacity that can provide a function as a power supply for at least one hour. The uninterruptible power supply 58 is automatically activated when the commercial power supply is cut off for some reason and when the heating means 32 is turned off for any reason. It is prepared in advance.

  The procedure of the annealing process of the high-pressure annealing apparatus 10 shown in the drawing is obvious to those skilled in the art. Although it will not be described in detail, the operation will be briefly described. A workpiece, that is, an article to be processed (not shown) is disposed by a known means. Thereafter, the reaction vessel 20 and the pressure vessel 12 are sealed. Air is removed from the inside of the annealing chamber 28 via the first exhaust pipe 38. The heater 32 is activated and a processing gas is supplied from the first air supply pipe 34 into the annealing chamber 28 to define predetermined annealing conditions. Annealing is performed for a predetermined time under these conditions. Thereafter, the workpiece that has been annealed is taken out of the annealing chamber 28. Annealing is performed by sequentially repeating such operations.

  If the commercial power supply that is regularly used is suddenly cut off during the annealing process due to lightning, power line disconnection, terrorist incident, blackout due to other unexpected causes, or accidental work mistakes by workers Furthermore, when an unexpected failure or the like such as the heater 32 itself or the wiring related to the heater occurs, the heater 32 does not function. Therefore, the temperature inside the reaction vessel 20 starts to drop from the working temperature, for example, 600 ° C. As a result, the pressure inside the reaction vessel 20 starts to gradually decrease. When this state is left as it is, the inside of the reaction vessel 20 is in a reduced pressure state. On the other hand, the pressure in the air space 30 surrounding the outside of the reaction vessel 20 is maintained at a high pressure during the annealing process. As a result, if this state is left as it is, the reaction vessel 20 formed of quartz glass or the like that is usually lacking in viscosity and rich in brittleness receives a suction force from the inside and receives a pressing force from the outside. As a result, it is clear that the expensive reaction vessel 20 is eventually broken into fine dust and broken.

  In general, there are two methods for dealing with such an accident. One is a method of compensating the decompressed state inside the reaction vessel 20 by supplying a reaction gas into the reaction vessel 20 from the outside of the annealing apparatus 10 via the first air supply pipe 34. Another method is to reduce the pressure in the air space 30 surrounding the reaction vessel 20 in accordance with the reduced pressure state of the reaction vessel 20. However, in the first method, a normal temperature gas is rapidly supplied from the outside, and as a result, the gas lowers the temperature in the vessel 20 more rapidly in the reaction vessel 20. For this reason, the internal pressure of the reaction vessel 20 is reduced more rapidly. As a result, although the damage accident of the reaction vessel 20 is increased, it does not help at all to prevent the reaction vessel 20 from being damaged. In addition, there is a risk that the work in the reaction container 20 will break due to the sudden introduction of ambient temperature gas from the outside, and dust enters the reaction container together with such gas introduction and the work There is a risk of contamination and a secondary loss of work damage will occur.

  On the other hand, in the second method, the pressure in the air space 30 is reduced in response to the reduced pressure in the annealing chamber 28, so that further pressure reduction or workpiece damage in the annealing chamber as in the first method. Although there is no danger of generating a secondary loss, the pressure in the air space 30 is constantly adjusted while, for example, the valve means 50 is opened while detecting the pressure in the annealing chamber 28 inside the reaction vessel 20. It is necessary to gradually reduce the pressure so as to correspond to the decrease value. This presupposes that the operator is always in the vicinity of the high-pressure annealing apparatus 10, knows that the heater 32 has stopped functioning, and adjusts and opens the valve means 50 of the second exhaust pipe 46. Therefore, it does not function at all in the case of such unexpected incidents.

  As another aspect of the second method, it is conceivable to cause the valve means 52 attached to the first exhaust pipe 38 to function. However, the valve means 52 is normally configured to respond to pressure by a coil spring, and it is difficult to operate sensitively to a slight pressure difference as sensed by the pressure sensor. In general, the temperature in the airspace 30 where the valve means 52 is located is about 100 ° C. or less. As a result, the valve means 52 is configured to react sensitively to a slight pressure difference, and the gas in the air space 30 is supplied into the annealing treatment chamber 28 via the valve means 52 to react. An attempt to compensate for the pressure difference between the inside and outside of the container 20 provides the same problem as the first method, which is not preferable.

  Therefore, the present invention is different from any of these methods, and the protection of the reaction vessel that can prevent damage to the expensive reaction vessel by an excellent method that completely eliminates the disadvantages of these two methods. A method and apparatus is disclosed. That is, as described above, in the apparatus of the present invention, the first exhaust pipe 38 communicating with the annealing chamber 28 inside the reaction vessel 20 and the annealing chamber 28, which can be operated independently, respectively. And a second exhaust pipe 46 communicating with the surrounding airspace 30. Further, these exhaust pipes 38, 46 are provided with pressure sensors 54, 56 connected to the uninterruptible power supply 58, respectively. The uninterruptible power supply 58 is set to start immediately when the commercial power supply is stopped or the heater 32 is deactivated.

  Thus, if the commercial power supply is cut off for some reason, or if the heater 32 becomes inoperable due to a failure or other reason, the uninterruptible power supply 58 is immediately activated. For this reason, the pressure sensors 54 and 56 connected to the uninterruptible power supply 58 are activated. These sensors 54 and 56 activate the automatic valves 40 and 50, respectively. These automatic valves 40 and 50 each function as a pressure regulator for adjusting the pressure inside the annealing chamber 28 and as a pressure regulator for adjusting the pressure in the air space 30. Accordingly, when the heater 32 is inactivated and the temperature in the annealing chamber 28 decreases and the pressure in the processing chamber 28 decreases, these sensors 54 and 56 operate in synchronization with each other to operate the automatic valves 40, By making the function 50 function, it is possible to adjust the automatic valve 50 of the second exhaust pipe 46 so that the pressure dropped in the annealing chamber 28 and the pressure in the air space 30 surrounding the pressure are always kept at the same pressure. . As a result, the pressure inside and outside the annealing chamber 28 is always balanced, and damage to the reaction vessel 20 can be completely prevented. Note that it will take approximately one hour for the temperature of the annealing chamber 28 to return to room temperature. However, if a longer time is required, it is desirable to increase the capacity of the uninterruptible power supply accordingly. In this method, since the uninterruptible power supply 58 is activated at the same time as detecting the malfunction of the heater 32 and activates the pressure sensors 54 and 56, the worker is always in the vicinity of the high-pressure annealing apparatus 10 and the malfunction of the heater 32 is prevented. It is not necessary to detect it, and the safety of the annealing chamber 28 is ensured even if the heater 32 becomes inoperative in an unattended state.

It is the schematic of the high pressure annealing apparatus of this invention.

Explanation of symbols

10: High pressure annealing device 12: Pressure vessel 14: Upper vessel 16: Lower vessel 18: Sealing means 20: Reaction vessel 22: Reaction vessel body 24: End cap 26: Sealing means 28: Annealing chamber 30: Air space 32: Heater 34 : First air supply pipe 36: valve means 38: first exhaust pipe 40: valve means 42: annular groove 44: second air supply pipe 46: second exhaust pipe 48: valve means 50: valve means 52: valve means 54: pressure Sensor 56: Pressure sensor 58: Uninterruptible power supply

Claims (2)

The pressure vessel 12, the reaction vessel 20 accommodated in the pressure vessel 12, and heater means disposed around the reaction vessel 20 in the air space 30 defined between the pressure vessel 12 and the reaction vessel 20 32, when the temperature inside the reaction vessel 20 drops due to the inoperative operation of the heater means 32 and the internal pressure of the reaction vessel 20 is reduced, the reaction vessel 20 is A method of protecting against damage,
Prepare a pressure sensor that responds to pressure fluctuations inside the reaction vessel,
Prepare a pressure sensor that responds to pressure fluctuations in the airspace,
Connect these pressure sensors to an uninterruptible power supply that starts immediately when the heater means is inoperative;
Maintaining the pressure inside and outside the reaction vessel at the same value by lowering the pressure outside the reaction vessel while synchronizing both pressure sensors;
A method for protecting a reaction vessel of a high-pressure annealing apparatus comprising the following steps. The method for protecting a reaction vessel according to claim 1,
Providing a first tube means communicating with the interior of the reaction vessel;
Connecting an automatic valve to the first pipe means;
Providing a second pipe means communicating with the interior of the airspace;
Connecting an automatic valve to the second pipe means;
Attaching a pressure sensor to each of the first tube means and the second tube means;
Connecting each pressure sensor to the automatic valve of each pipe means,
Connecting these pressure sensors to an uninterruptible power supply,
Be prepared to start the uninterruptible power supply immediately when the heater means becomes inoperative;
When the heater means became inoperative and the pressure sensor attached to the first pipe means sensed the pressure fluctuation in the reaction vessel and activated the automatic valve of the first pipe means, it was attached to the second pipe means in response thereto. Holding the pressure inside and outside the reaction vessel at an equal value by activating the automatic valve of the second tube means in response to the pressure sensor to lower the pressure outside the reaction vessel;
The method for protecting a reaction vessel of a high-pressure annealing apparatus according to claim 1, comprising the following steps.

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